Board Thread:Pokémon Help/@comment-26505627-20161108194554/@comment-26896136-20170328101555

In my opinion, Mudkip is the best starter.

1st Gym - Electric: Mudkip evolves into Marshtomp easily, requiring minimal grinding. This will make Marshtomp immune to Electric because of it's Ground typing.

2nd Gym - Fire: This is easy pickings for Marshtomp

3rd Gym - Water: Marshtomp should have evolved into Swampert by now, and can tank hits that are normal effectiveness. Nonetheless, I brought along additional Pokemon, but they weren't needed.

4th Gym - Flying: Swampert's Rock Slide will 1- or 2-Shot every Pokemon while tanking hits, allowing it to survive until Braviary, the last Pokemon even if you are not skilful. Bring along another Pokemon and it should be easy.

5th Gym - Ground: Just 1-Shot everything with Scald (Learn via TM), including Mega-Garchomp.

6th Gym - Grass: This is where Swampert gets a bit weak. You have to get TM: Ice Beam and teach it to him if you want him to sweep the gym. Defeat all the trainers, then battle the Gym Leader. If needed, heal Swampert up to regain PP for Ice Beam. I used weaker Pokemon such as Lucario against the trainers to save Swampert's Ice Beam. Now, bring Swampert up for the Gym Leader. It should be alright until Mega-Venusaur, who will 1-Shot you with Solar Beam. Nonetheless, you should be able to get off 1 shot with Ice Beam, bringing it to around half-health. I used a Charizard to take care of it. Note that I used Mega-Swampert  for the 5th and 6th Gym.